JPH0217741B2 - - Google Patents
Info
- Publication number
- JPH0217741B2 JPH0217741B2 JP589285A JP589285A JPH0217741B2 JP H0217741 B2 JPH0217741 B2 JP H0217741B2 JP 589285 A JP589285 A JP 589285A JP 589285 A JP589285 A JP 589285A JP H0217741 B2 JPH0217741 B2 JP H0217741B2
- Authority
- JP
- Japan
- Prior art keywords
- cross
- section
- coil
- stress
- coil spring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000004458 analytical method Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 230000005484 gravity Effects 0.000 description 5
- 238000012935 Averaging Methods 0.000 description 1
- 241000282485 Vulpes vulpes Species 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F1/00—Springs
- F16F1/02—Springs made of steel or other material having low internal friction; Wound, torsion, leaf, cup, ring or the like springs, the material of the spring not being relevant
- F16F1/04—Wound springs
- F16F1/042—Wound springs characterised by the cross-section of the wire
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Springs (AREA)
Description
（産業上の利用分野）
本発明は、コイルばね、特に、その素線の断面
形状が半円と半楕円の組み合わせからなり、断面
周上の応力を均一化し、その最大応力の低減を図
つたコイルばねに関する。
（従来技術）
最近、自動車の軽量化が図られる中で、エンジ
ンの弁ばねやクラツチのトーシヨンばね等におい
て、限られたスペース内に収容できしかも軽量で
あるばねを設計する必要性が生じてきた。このこ
とは、ばね圧縮時の密着長を出来るだけ小さく
し、しかも一定量のエネルギーを吸収する重量を
小さくすること、すなわち、エネルギー効率を向
上させるということである。
ところで、ばねの密着長HSは一般に次式によ
り算出される。
HS＝（Ｎ−0.5）ｔ ……(1)
ここで、
Ｎ：総巻数
ｔ：素線の縦方向寸法。
つまり、密着長を小さくするには、総巻数Ｎを
少なくし、素線の縦方向寸法ｔを小さくすればよ
い。また、エネルギー効率を向上させるには、断
面周上の応力を均一化し、最大応力を低くすれば
よい。
一般に、コイルばね素線は円形断面のものが従
来から用いられている。しかしながら、この円形
断面コイルばねに軸荷重が作用すると、断面周上
の発生応力は、周知のごとく、コイル素線がわん
曲している影響と直接せん断力により、コイル内
側の応力が増大し、エネルギー効率が悪い。この
最大応力τmaxは次のワールの式により求まる。
τmax＝8DP／πd3（4C−１／4C−４＋0.615／Ｃ）
……(2)
ここで、Ｃはばね指数と呼ばれるもので、断面
中心間のコイル径をＤ、素線の直径をｄとしたと
き、
Ｃ＝Ｄ／ｄ
である。なお、Ｐは荷重である。
このような応力の増大する欠点を改良したもの
として、特公昭27−3261号および米国特許第
2998242号のものがある。前者は、素線断面が卵
形状であるとしているが、応力を低減するための
素線断面寸法については明確にしていない。ま
た、後者は、その形状を半円と半楕円の組み合せ
であるとし、その断面の長径ｗと短径ｔとの関係
を次式で決定するとしている。
ｗ／ｔ＝１＋1.2／Ｃ ……(3)
ここで、Ｃ＝Dm／Ｗ、Dm：断面の中心間の
コイル径。
これら両者とも、素線断面を偏平にすることに
より、密着長を小さくできる点については効果が
ある。しかし、これらを弾性力学に基づいた解析
手法により応力解析を行うと、応力均一および最
大応力を低減するという点からは、必ずしも十分
ではない。
（発明が解決しようとする問題点）
本発明は、従来の材料力学的解法では任意断面
形状の応力解析が非常に困難であるため、断面外
周境界を多数の線素に分割し、線素を直線近似
し、各線素に沿つてフーリエ展開を施し、それを
境界全域に拡張するという、弾性力学に基づいた
解法（フーリエ展開境界値平均法）により応力解
析し、特に、従来のものに比してその断面周上の
応力の均一化および最大応力の低減化をより図
り、また、それにより素線の細線化を図り、密着
長の短縮および重量を大幅に低減した、コイル外
周側が半円形状でコイル内周側が半楕円形状の素
線断面のコイルばねを提供することを目的とする
ものである。
（問題点を解決するための手段）
本発明のコイルばねは、第１図に示すように、
コイル素線の断面形状が、コイル外周側が半円形
状で、コイル内周側が半楕円形状であり、その断
面の長径ｗと短径ｔとの比がほぼ次式の関係にあ
る。
ｗ／ｔ＝１＋0.55／Ｃ ……(4)
ここで、Ｃ＝Dm／Ｗ、Dm：断面の中心間の
コイル径
（作用）
上記の関係を満たすコイルばねにあつては、断
面周上の応力は従来の円形断面のコイルばね、先
の(3)式で決定される従来のコイルばねに比べて、
均一化されており、最大応力もより小さい。
応力分布の解析は、コイル重心径DGを一定、
軸荷重Ｐを一定、断面積を一定（πd2／４＝
πwt／４）、倒れ角、ピツチ角0゜の条件の下で、
ｗ／ｔを0.1ずつ変化させ、応力が最も小さくな
るｗ／ｔを求めた。その結果を第３図に示す。横
軸はｗ／ｔであり、縦軸はβ＝τmax／τ0（ただし
τmaxはFECM解の最大応力値、τ0は丸線の未修
正応力）である。尚、DG／ｄ＝DG／√は３、
４、５、６、７、８の６種類とし、図中にC′とし
て表示してある。
この応力の最低点ａ、ｂ、ｃ、ｄ、ｅ、ｆを
ｗ／ｔと１／Ｃ（Ｃ＝Dm／ｗ）に関してプロツ
トした結果を第４図に示す。この理想断面は式(4)
で近似されることが明らかであり、Fuchsの断面
形状からは大きくずれている。
（実施例）
以下、図面を参照にして本発明の実施例を詳細
に説明する。
素線が円形断面以外の任意断面を有するコイル
ばねについては、従来の材料力学的解法では断面
周上の応力を求めることができない。そこで、先
に述べたように、本発明において効率的なコイル
ばねを求めるために、フーリエ展開境界値平均法
（Fourier Expansion Colocation Method、Ｆ、
Ｅ、Ｃ、Ｍ）を用いた。この解法は、断面外周境
界を多数の線素に分割し、線素を直線近似し、各
線素に沿つてフーリエ展開を施し、それを境界全
域に拡張するという、弾性学に基づいた解法であ
る。
第１図は、本発明の実施例を示したものである
が、図において、DGは断面の重心間のコイル径
を示し、Dnは断面の中心間のコイル径を示す。
本発明のコイルばねの素線の断面形状は、コイル
外周側の半円とコイル内周側の半楕円と組み合せ
により構成されている。これは、従来の米国特許
第2998242号のものと同一であるが、Ｆ、Ｅ、Ｃ、
Ｍ、を用いて求めた結果、最大応力が最低となる
本発明のコイルばね素線の断面の長径Ｗと短径ｔ
との比は次式の関係にある。
Ｗ／ｔ＝１＋0.55／Ｃ（ここでＣ＝Dm／Ｗ） ……(5)
第２図は、従来の円形断面素線のコイルばね、
(3)式で決定される従来の異形コイルばね、およ
び、(5)式で決定される本発明のコイルばねそれぞ
れの断面周上の応力解析を行つた結果、得られた
応力分布を示すものである。この場合のそれぞれ
の素線断面積を同一としたばね仕様を次表に示
す。
(Industrial Application Field) The present invention provides a coil spring, in particular, a coil spring whose cross-sectional shape is a combination of a semicircle and a semi-ellipse, which equalizes the stress on the cross-sectional circumference and reduces the maximum stress. Regarding coil springs. (Prior art) Recently, as automobiles have become lighter, it has become necessary to design springs that can be accommodated in a limited space and are lightweight, such as engine valve springs and clutch torsion springs. . This means making the contact length as small as possible when the spring is compressed and reducing the weight that absorbs a certain amount of energy, that is, improving energy efficiency. By the way, the tight contact length H S of the spring is generally calculated by the following formula. H S = (N-0.5)t...(1) Here, N: Total number of turns t: Vertical dimension of the strand. That is, in order to reduce the adhesion length, the total number of turns N may be reduced and the longitudinal dimension t of the strands may be reduced. Furthermore, in order to improve energy efficiency, it is sufficient to equalize the stress on the circumference of the cross section and lower the maximum stress. Generally, coil spring wires having a circular cross section have been conventionally used. However, when an axial load is applied to this circular cross-section coil spring, the stress generated on the circumference of the cross-section increases due to the influence of the bending of the coil wire and direct shear force, and the stress inside the coil increases. Poor energy efficiency. This maximum stress τmax is determined by the following Wahl's equation. τmax=8DP/πd 3 (4C-1/4C-4+0.615/C)
...(2) Here, C is called a spring index, and when the coil diameter between the centers of the cross section is D and the diameter of the strand is d, C=D/d. Note that P is a load. Japanese Patent Publication No. 27-3261 and U.S. Pat.
There is one numbered 2998242. The former states that the cross section of the wire is egg-shaped, but does not clarify the cross-sectional dimensions of the wire for reducing stress. The latter shape is a combination of a semicircle and a semiellipse, and the relationship between the major axis w and the minor axis t of the cross section is determined by the following equation. w/t=1+1.2/C...(3) Here, C=Dm/W, Dm: Coil diameter between the centers of the cross section. Both of these methods are effective in that the adhesion length can be reduced by making the wire cross section flat. However, performing stress analysis on these using an analysis method based on elastic mechanics is not necessarily sufficient in terms of stress uniformity and reducing the maximum stress. (Problems to be Solved by the Invention) Since stress analysis of an arbitrary cross-sectional shape is extremely difficult with conventional material mechanics solution methods, the present invention divides the outer peripheral boundary of the cross-section into a large number of line elements. Stress analysis is performed using a solution method based on elastic mechanics (Fourier expansion boundary value averaging method) that approximates a straight line, performs Fourier expansion along each line element, and extends it to the entire boundary. The outer periphery of the coil is semicircular, which further equalizes the stress on the cross-sectional circumference and reduces the maximum stress.As a result, the strands are made thinner, shortening the adhesion length and significantly reducing the weight. It is an object of the present invention to provide a coil spring having a cross section of a wire whose inner circumferential side is semi-elliptical. (Means for solving the problem) As shown in FIG. 1, the coil spring of the present invention has the following features:
The cross-sectional shape of the coil wire is semicircular on the outer circumferential side of the coil and semi-elliptic on the inner circumferential side of the coil, and the ratio of the major axis w to the minor axis t of the cross section is approximately in the following relationship. w/t=1+0.55/C...(4) Where, C=Dm/W, Dm: Coil diameter between the centers of the cross section (action) For a coil spring that satisfies the above relationship, on the circumference of the cross section Compared to a conventional coil spring with a circular cross section, the stress of is determined by the equation (3) above,
It is more uniform and the maximum stress is also smaller. In the analysis of stress distribution, the diameter of the center of gravity of the coil D G is kept constant.
The axial load P is constant, the cross-sectional area is constant (πd 2 /4=
πwt/4), under the conditions of tilt angle and pitch angle of 0°,
W/t was changed in increments of 0.1, and the w/t at which the stress was the smallest was determined. The results are shown in FIG. The horizontal axis is w/t, and the vertical axis is β=τmax/τ 0 (where τmax is the maximum stress value of the FECM solution, and τ 0 is the uncorrected stress of the round line). In addition, D G /d=D G /√ is 3,
There are six types, 4, 5, 6, 7, and 8, and they are indicated as C' in the figure. FIG. 4 shows the results of plotting the lowest stress points a, b, c, d, e, f with respect to w/t and 1/C (C=Dm/w). This ideal cross section is expressed by formula (4)
It is clear that the cross-sectional shape is approximated by , and it deviates greatly from the Fuchs cross-sectional shape. (Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. For a coil spring whose strands have an arbitrary cross section other than a circular cross section, the stress on the circumference of the cross section cannot be determined using conventional material mechanics solutions. Therefore, as mentioned above, in order to obtain an efficient coil spring in the present invention, the Fourier Expansion Colocation Method (F) is used.
E, C, M) were used. This solution method is based on elasticity, which divides the cross-sectional outer boundary into many line elements, approximates the line elements to a straight line, performs Fourier expansion along each line element, and extends it to the entire boundary. . FIG. 1 shows an embodiment of the present invention. In the figure, D G indicates the coil diameter between the centers of gravity of the cross section, and D n indicates the coil diameter between the centers of the cross section.
The cross-sectional shape of the wire of the coil spring of the present invention is constituted by a combination of a semicircle on the outer circumferential side of the coil and a semiellipse on the inner circumferential side of the coil. This is identical to that of previous US Pat. No. 2,998,242, but with F, E, C,
The major axis W and minor axis t of the cross-section of the coil spring wire of the present invention, which have the lowest maximum stress
The ratio with is in the following relationship. W/t=1+0.55/C (here C=Dm/W)...(5) Figure 2 shows a conventional coil spring with a circular cross-section element wire.
This shows the stress distribution obtained as a result of stress analysis on the cross-sectional circumference of the conventional irregular-shaped coil spring determined by equation (3) and the coil spring of the present invention determined by equation (5). It is. In this case, the spring specifications with the same cross-sectional area of each strand are shown in the table below.
【表】
第２図は、ばねに作用する荷重20Kgの場合の応
力分布を示し、横軸は第１図で示した重心点Ｇの
まわりの角度θであり、コイル内側を0゜とし、コ
イル外側が180゜としている。縦軸は断面周上の各
点の応力を示したものである。Ａは従来の円形断
面のもの、Ｂは従来の異形断面のもの、Ｃは本発
明のものである。この比較したグラフより、円形
断面のものＡはコイル内側にピーク値があり、ま
た、従来の異形のものＢは角度60゜付近にピーク
値があり、それぞれ応力は均一ではない。これに
対して、本発明のものは０〜60゜付近まで応力は
ほぼ均一となり、最大応力τmaxも従来のいずれ
のものより小さい。
（発明の効果）
以上、実施例から明らかなように、(4)式の関係
にある本発明のコイルばねにおいては、断面周上
の応力はほぼ均一に分布しており、そのため、一
定量のエネルギーを吸収する重量をより小さくで
き、エネルギー効率を従来のものより向上させる
ことができる。
また、一般にばね寿命は断面周上の最大応力に
より決定づけられるので、本発明のばねは、従来
の半円と半楕円の組み合わせからなるもの、およ
び、同一断面積の円形断面のものより高寿命とな
る。
さらに、密着長に関しても、従来の円形断面の
ものより小さくできる。
これらから、ばね全体がコンパクトな設計とな
り、重量を大幅に改善でき、非常に効果が大き
い。[Table] Figure 2 shows the stress distribution in the case of a load of 20 kg acting on the spring. The horizontal axis is the angle θ around the center of gravity G shown in Figure 1. The outside angle is 180°. The vertical axis indicates the stress at each point on the circumference of the cross section. A is a conventional one with a circular cross section, B is a conventional irregular cross section, and C is one of the present invention. The comparison graph shows that the circular cross-section type A has a peak value inside the coil, and the conventional irregular-shaped type B has a peak value around an angle of 60 degrees, so the stress is not uniform. On the other hand, in the case of the present invention, the stress is almost uniform from 0 to around 60 degrees, and the maximum stress τmax is also smaller than any of the conventional cases. (Effects of the Invention) As is clear from the examples above, in the coil spring of the present invention having the relationship expressed by equation (4), the stress on the cross-sectional circumference is almost uniformly distributed, so that a certain amount of stress The weight that absorbs energy can be made smaller, and energy efficiency can be improved compared to conventional ones. Additionally, since the spring life is generally determined by the maximum stress on the circumference of the cross-section, the spring of the present invention has a longer life than a conventional spring made of a combination of a semicircle and a semi-ellipse, and a spring with a circular cross-section of the same cross-sectional area. Become. Furthermore, the adhesion length can also be made smaller than that of the conventional circular cross section. As a result, the entire spring has a compact design, and the weight can be significantly reduced, which is extremely effective.
第１図は本発明のコイルばねの部分縦断面図、
第２図は応力分布図、第３図は断面形状と応力係
数の関係を示すグラフ、第４図は理想断面形状を
示すグラフである。
Ｗ：断面の長径、ｔ：断面の短径、Dm：断面
の中心間のコイル径、DG：断面の重心間のコイ
ル径、Θ：重心のまわりの角度。
FIG. 1 is a partial vertical sectional view of a coil spring of the present invention;
FIG. 2 is a stress distribution diagram, FIG. 3 is a graph showing the relationship between cross-sectional shape and stress coefficient, and FIG. 4 is a graph showing the ideal cross-sectional shape. W: Long axis of the cross section, t: Short axis of the cross section, Dm: Coil diameter between the centers of the cross section, D G : Coil diameter between the centers of gravity of the cross section, Θ: Angle around the center of gravity.
Claims (1)
形状でコイル内周側が半楕円形状を有するコイル
ばねにおいて、その断面の長径Ｗと短径ｔとの比
がほぼ次式の関係にあることを特徴とするコイル
ばね。 ｗ／ｔ＝１＋0.55／ｃ、 ここで、Ｃ＝Dm／Ｗ、Dm：断面の中心間の
コイル径。[Claims] 1. In a coil spring in which the cross-sectional shape of the coil wire is semicircular on the outer circumferential side of the coil and semielliptic on the inner circumferential side of the coil, the ratio of the major axis W to the minor axis t of the cross section is approximately expressed by the following formula: A coil spring characterized by the following relationship. w/t=1+0.55/c, where C=Dm/W, Dm: Coil diameter between centers of cross section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP589285A JPS61167728A (en) | 1985-01-18 | 1985-01-18 | Coil spring |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP589285A JPS61167728A (en) | 1985-01-18 | 1985-01-18 | Coil spring |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61167728A JPS61167728A (en) | 1986-07-29 |
| JPH0217741B2 true JPH0217741B2 (en) | 1990-04-23 |
Family
ID=11623546
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP589285A Granted JPS61167728A (en) | 1985-01-18 | 1985-01-18 | Coil spring |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61167728A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4923183A (en) * | 1987-10-20 | 1990-05-08 | Honda Giken Kogyo Kabushiki Kaisha | Non-circular cross-section coil spring |
| JP5257825B2 (en) * | 2007-05-08 | 2013-08-07 | 日立工機株式会社 | Driving machine |
| WO2009136514A1 (en) * | 2008-05-07 | 2009-11-12 | 株式会社東郷製作所 | Modified cross-section coil spring |
| JP5981958B2 (en) * | 2014-05-28 | 2016-08-31 | 三菱製鋼株式会社 | Suspension coil spring and strut suspension system |
-
1985
- 1985-01-18 JP JP589285A patent/JPS61167728A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61167728A (en) | 1986-07-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4854556A (en) | Device for damping shocks and vibrations | |
| AU626188B2 (en) | Coiled spring | |
| EP0184848B1 (en) | Composite spring | |
| US3161407A (en) | Vibration and shock absorber | |
| WO2009005946A1 (en) | Elastic shear band with columnar elements | |
| JP2778735B2 (en) | Coil spring device | |
| GB2041491A (en) | Helical compression spring | |
| JPH0217741B2 (en) | ||
| JPH0160705B2 (en) | ||
| USRE33696E (en) | Composite spring | |
| USRE30262E (en) | Compressive load carrying bearings | |
| JPS5813767B2 (en) | Coil spring seat | |
| JPS61105317A (en) | Coiled spring | |
| JPH0583774B2 (en) | ||
| US4744549A (en) | Coil spring for the wheel suspension of a motor vehicle wheel suspension system | |
| JP3938766B2 (en) | Compression coil spring | |
| JPH0623583B2 (en) | Coil spring | |
| KR200362818Y1 (en) | a coil spring | |
| JPS6321787Y2 (en) | ||
| JPH0248770B2 (en) | DAENDANMENSOSENNOKOIRUBANE | |
| JPS6249037A (en) | Composite spring for high rigid elastomer and metallic coil spring | |
| JP2003130108A (en) | Multi-stage coil spring device | |
| JPS6139134Y2 (en) | ||
| RU13074U1 (en) | SCREW CONIC CYLINDER SPRING | |
| JPH03244841A (en) | Rubber bush |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| EXPY | Cancellation because of completion of term |